html, body
    font-weight: 200
    font-family: 'PingFang SC', 'STHeitiSC-Light', 'Helvetica-Light', arial, sans-serif
border-1px($color)
    position relative
    &:after
        position absolute
        left: 0
        bottom: 0
        width: 100%
        border: 1px solid $color
        content: ''

base_image($url, $width, $height)
    background-image: url($url + '@2x.png')
    width: $width
    height: $height
    background-size: $width $height
    background-repeat: no-repeat
    @media (-webkit-min-device-pixel-ratio: 3), (min-device-pixel-ratio: 3)
        background-image: url($url + '@3x.png')
